With the rapid development of internet technology and global positioning system (GPS) technology, many instant messaging systems have also developed users geography location services, which facilitate sharing real-time geographical location viewable among different users. In other words, users who participate in sharing their locations may usually be able to view the most current locations of the peer users displayed on a same map through a viewable region on a map.
A viewable region on a map may display a portion of a geographical area in a map format which is viewable through a display screen on the terminal. However, due to the small and limited display screen size on the terminal, current viewable region on the map usually displays just a static map which is constant and fixed in geographical boundary. Therefore, if many users simultaneously share their locations in a same chat session, those users who are located far away from the location of the host user's terminal may not be included in a viewable region on the map due to screen size and resolution limitation. Alternately, users whose locations are changing (i.e., on a vehicle or walking) also may not be updated automatically to reflect their new current locations, or in case if they have moved to a new location outside the boundary of the viewable region on the map.
To simply put, not all the users who participate in sharing their locations may be displayed on the viewable region on the displayed map. The efficiency of acquiring all the most current locations of participating users who are diversely located or who constantly changes their locations may be quite poor.